He would need a spare loom or to make a custom loom in order to connect a consult cable. I think he's referring to a direct hookup with the Nistune daughterboard, which can probably be done with specific equipment that a tuning shop would own, but a home guy would not.

Tbh it would be easier to check the Nistune with the ECU plugged into a friend's car.

So did the OP get it sorted out and how so others might be helped out by it????
So often someone asks a question but can't be fucked posting the solution / outcome, and how they fixed so others can be helped out. Come on dude have you fixed your problem??? How???